Paper-feeding machine



May 27, 1930. 1 F. L. cRoss ET PAPER FEEDING MACHINE Filed May 12. 19266 Sheets-Sheet May 27, 1930. 1 1.. CROSS ET AL PAPER FEEDING MACHINEFiled May 12, 1926 6 Sheets-Sheet 2 May 27, 1930. CROSS ET AL PAPERFEEDING MACHINE s Sheets-Sheet 5 Filed May 12, 1926 May 27, 1930. CROSSET AL PAPER FEEDING MACHINE I 6 Sheets-Sheet Filed May 12, 1926 Ma 27,1930. F. CROSS ET AL. 1,760,119

PAPER FEEDING MACHINE Filed May 12. 1926 6 Sheets-Sheet e M67060?" myChm over a lower feed table.

Patented May 27, 1930 UNITED STATES PATENT OFFICE,

FRANK L. CROSS, OE PORT A CORPORATION OF MASSACHUSETTS WASHINGTON, NEWYORK, AND HENNING HALLSTREAM, 0F BRAINTREE, MASSAQHUSETTS, ASSIGNORS 'IOCROSS PAPER FEEDER COMPANY,

PAPER-F EDING MACHINE Application filed May 12,

The present invention relates to paper feeding machines of thecontinuous bank type which are intended to separate individual sheetsfrom the bank and forward them in 5 regular succession to a printingpress or similar machine.

In this type of machine a bank of feathered or fanned-out sheets is fedfrom an upper delivery table, through a reversing throat and From thispoint the top sheet is ordinarily separated from the bank and deliveredto the press through combing devices which engage with the surfaces ofthe top sheets and forward them in regular sequence.

satisfactorily in the majority of cases, but under certain conditions itmay be desirable to accomplish the separation and delivery of the topsheet without a rubbing or combing action which may cause a smearing ordefacement of the sheet if the ink is not completely dry.

Accordingly, one object of the present invention is to permit theseparation and delivery of individual sheets of varying size from acontinuous bank of featheredsheets without smearing or defacing theprinted surface of the sheet and to perform this operation independentlyof the extent of the printed area. This is accomplished simply andexpeditiously by engaging the top sheet of the feathered bank withsuction gripping devices which operate to elevate the sheet bodily fromthe underlying bank and deliver the sheet to the gripping devices of thepress.- Operating in conjunction with the suction grippers are hold-downdevices, which engage thesecond sheet of the bank and clamp it inposition dursheet. The bodily separation of the top sheet from the bankin this manner enables it to be properly separated and delivered to thepress without conveying it beyond the front edge of the bank as wouldotherwise be necessary if 5 the mechanism had accomplished theseparation through a rubbing and sliding action. This mode of operationobviously results in a considerable saving of space especially whenfeeding sheets of large size.

A further object of the present invention The combing mechanism operatesing the separation and removal of the top-1 1926. Serial N0. 108,546.

is to provide sheet feeding apparatus applicable to existing machinesand easily adjusted to handle sheets of widely varying length and width.A still further object of the invention is to provide mechanism forstopping the press or other machine in the event either that the sheetis not delivered to the gripping devices of the press; is improperlydelivered to the registering mechanism by the pull-up guides; or isgripped in such a manner that it does not hug the cylinder of the pressclosely. To this end properly disposed feeler members are connected withstop mechanism continuously driven from the moving parts of the machineand operating upon occurrence of either or both of the contingencies toautomatically stop the operation of the press.

A still further feature of the invention consists in certain novelfeatures, constructions, combinations and arrangements of partshereinafter described and claimed, the advantages of which will beobvious to those skilled in the art from the following description:

Fig. 1 is a side elevation of the sheet separating and deliverymechanism embodied in. the printing press;

Fig. 2 is a detail partly in section illustrating the sheet deliverymechanism at the commencement of the delivery movement;

Fig. 3 is a view similar to 2 illustrating the delivery and separatingmechanism after the top sheet has been removed from the bank and duringits passage from the bank to the gripper members;

Fig. 4 is a detail showinga side elevation of the mechanism for stoppingthe machine in the event that no sheet is delivered to the grippermembers or in the event that a sheet so delivered is improperly held bythe gripper 'members. Fig. 4 also illustrates the position of thepneumatically-operated delivery members after delivery of a sheet to thegripper members;

Fig. 5 is a rear elevation of the mechanism shown in Fig. 1, showingmore particularly the mechanism for separating the top sheet from thebank prior to its engagement and delivery to the gripper members;

Figs. 6 and 7 are details illustrating the operation of engaging andbuckling the rear corners of the top sheet and separating the K sheetfrom the bank; and

Fig. 8 is a detail illustrating a section of the valve mechanism foroperating the pneumatic separating and delivery mechanism.

' According to the illustrated embodiment of the invention, the topsheet of a reviously formed bank is separated and de iveredv atpredetermined intervals to the cylinder of a printing press of theMiehle type. The sheet separating and delivery mechanism operatesautomatically in timed relation to the operation of the press, and maybe applied to presses of this type without change or alteration in themechanism of the press. The separation and delivery of individual sheetsfrom a bank of sheets is accomplished essentially by engaging andelevating or buckling the rear outer corner of the top sheet from thebank of'sheets therebeneath. With the rear corners of the sheets thusengaged and elevated, a current of air is interposed between the topsheet and the remaining 8 sheets of the bank to vibrate or flutter theedge portion and substantially complete the separation. .With the rearcorners so ele- .vated and the body of the sheet separated from the mainbank, the front portion of the sheet is engaged pneumatically and thesheet bodily conveyed to gripper members of the usual form mounted onthe cylinder of the 6 press. This cycle of operations is repeated toseparate and deliver a sheet during each two revolutions of thecylinder.

The bed of the press is indicated generally at 20 and is provided withan inclined table 22. Supported on the bed is the bank conveyor andsheet separating and delivery mechanism. The sheets to be delivered arecontained initially in the upper compartment 24, supported on theinclined frame 25, and removed from the compartment in the usual mannerby an endless conveyor 26. The conveyor 26 operating in conjunction witha conveyor 28 removes a continuous bank of sheets from the compartment24 to the position indicated at 30, in which the sheetsare fanned out inthe usual manner to afford opportunity for the operation of theindividual sheet separating and delivery mechanism. The mechanism forconveying the bank of sheets to the point of pickup by the separatingand delivery mechanism may be of any usual character and forms no partspecifically'of the present invention. 1

The mechanism for separating the top.

sheet from the bankat predetermined intervals is illustrated moreparticularly in Figs. 1, 3, 5 and 6. This is accomplished by pneumaticgrippers or bucklers 32 and 33 which are adapted to engage and elevatethe outer rear corners of the top sheet. Each of these pneumatic memberscomprises essentially a cup 34 of soft, flexible rubber whichis-normally positioned above the top sheet, the inasindicated moreparticularly in Fig. 5. p

This downward movementef the suction cups is accomplished by a collar 40connected to each cup and provided with an operating rod 42 connected atits opposite end with a cam lever 44. The lever 44 is pivoted at 46 andis provided with a camroll 48 between its ends, which contacts with theperiphery of a cam 50, more particularly shown in Fig. 5. This cam ismounted upon a shaft 52 journaled within a sliding upright 54 supportedin the head 56 and a bracket 98 bolted to the upright, as indicated inFig. 3. The shaft 52 is continuously rotated during the operation of thepress through telescoping shafts 58, 60 and universal joints 62, 64. Asindicated more particularly in Fig. 5, each'su'ction gripper member issupported bya separate slide 54 and is operated by a separatetelescoping drive shaft. The cam 50 is designed to permit depression ofthe suction members into engagement with the upper sheet and to reintocontact with the surface of the sheet, the

latter is engaged by the hold-downs 38, 39,

but prior to. the elevation of the gripper members to buckle the cornersof the sheet, the outer hold-downs 39 are removed from the sheet, asindicated more particularly in Fig. 6. Each hold-down 39 consists of anarm 66 pivoted at 67 and connected to the operating lever 69 through alink 70. The operating lever 69 is fulcrumed at 72 and is normallydesigned to elevate the hold-down by virtue of a spring 74 engaging witha tail 76 formed upon the lever adjacent the fulcrum. The position ofthe lever and hold-down is controlled by a cam 78 mounted upon the shaft52 and contacting with a cam roll 80 journaled upon the outer end of thelever. Cooperating with the outer hold-down 39 is the inner hold-down 38This inner hold-down is formed upon an arm 82 fulcrumed at 84 andoperated through a lever 86 and link 88. Lever 86 is also fulcrumed at72 and is normally designed to retain the hold-down in an elevatedposition through a spring 89. The position of the lever and hold-down iscontrolled by a cam 90 mounted upon the shaft 52 contacting with a camroll 92 journaled on the lever. In the usual operation of the separatormechanism, the outer hold-down is first elevated to permit buckling thecorner of the upper sheet through theadjacent suction gripper 34. Duringthis buckling movement the body of the sheet is retained in position bythe inner hold-downs 38. Subsequent to the buckling of the corner theouter holddown is returned to its initial position to engage the bank ofsheets underlying the upper sheet, as indicated in Fig. 7 and the innerhold-downs are elevated to permit removal of the separated sheet. Thecomplete separation of the sheet which has been buckled by elevation ofthe corners is aided by the interposition of air between the sheetandthe bank of sheets therebeneath. This is accomplished through theemployment of nozzles 93 postioned adjacent opposite corners of thesheet and arranged to direct currents of air beneath the sheet after thebuckling has taken place. These nozzles, as indicated more particularlyin Figs. 3, 5, 6 and 7,

are formed at the lower ends of downwardly extending conduits 94 whichare mounted in fixed arms 96 forming a part of the bracket 98 bolted tothe slide 54. It will be evident that with this construction thehold-down members are retained in engagement with the bank of sheetsthrough the weight of the sliding upright and parts supported thereby.By virtue of this construction the position of the hold-downs ispermitted to vary in accordance with the height of the bank. The outerhold-downs 39 are provided with antifriction rolls to permit movementsof the bank thereunder, this movement taking place during replenishmentof the bank.

After the separation of the upper sheet from the remaining sheets in thebank through engagement and buckling of the rear portion, the sheet isengaged adjacent its front portion and delivered to the mechanism of thepress. This is accomplished by pneumatic members operatingintermittently and in timed relation to the separator mechanism; Asshown more particularly in Figs. 2 and 3, the top sheet is engagedadjacent the front corner portions by suction grippers 100. Each ofthese grippers comprises a flexible cup mounted in the lower end of asleeve 102- telescoping within a second sleeve 104. The grlpplng cup 1snormally maintained in a sheet-engaging position by a light spring 106surrounding a rod 108 which is attached at its lower end to'a collar 110and at its upper.

end slides freely through a boss 112 projecting from the Sleeve 104.Each gripping member is supported for a longitudinal movement with aslide 111 which is movable between guides 114 secured to side bars 116,as shown more particularly in Fig. 5. The slides 111 mounted at oppositesides of the feed mechanism are reciprocated by mechanism driven in anysuitable manner from the main shaft of the press (not shown). Thismechanism, as shown more particularly in Figs. 2, 3 and 5, comprises avertical drive shaft 118 operating a cross shaft 120 throughintermeshing bevels 122 and 124 shown in dotted lines in Fig. 2. Thecross shaft 120 carries a small pinion 126 which meshes with a largespur gear 128 mounted upon a shaft 130. The large gear 128 is providedwith a crank pin l32 connected with a rack bar 134 sliding in a guide136 which is mounted for oscillatory movement about a shaft 138. Theteeth 140 of the sliding rack mesh with a small pinion 142 mounted onthe shaft 138 which also carries a larger gear'144 meshing in turn withthe teeth 146 on the suction gripper slide 111. As indicated moreparticularly in Fig. 5, both of the shafts 130 and 138 extendtransversely of the machine and the shaft 138 is provided with twooppositely disposed gears 144 which mesh respectively with the twoslides'lll. By virture of this mechanism a reciprocatory motion in timedrelation to the operation of the press is imparted to the suctiongrippers 100, this motion serving to advance the grippers fromapproximately the position shown in Fig. 2,

ment of the gripper is accomplished through the telescoping connectionbetween the sleeve 102 and the outer sleeve 104, moving the sleeves fromthe relative position shown in Fig. 1 to that shown in Figs. 2 and 3,and serving to elevate the gripper members and the front edge of thesheet above the top of the stop member 152. At the completion of thefeeding movement, it is desirable to release the suction and elevate thegripper members above the sheet to avoid interference upon the return ofthe grippers. This elevating movement of the grippers is convenientlyaccomplished in the present mechanism by supporting each suction gripperassembly by an arm 154 which is connected to a cross rock shaft 156.This cross rock shaft is journalled at opposite ends in brackets 160bolted to the gripper slideslll. The two gripper slides are incidentallyconnected by a transverse shaft 162 mounted at its opposite ends in thebrackets 160, as shown more particularly in Fig. 5. The verticalposition of the grippers is determined by the engagement of a roll 164mounted on the outer end of an arm 166 with the upper sur-- face of arail 168. The arms 154 and 166 are connected through the rock shaft toform, ineifect, bell crank levers and cause the position of the gripperassemblies to be determined by the position of the arm 166. The

positioning rail 168 is normally stationary but is varied in height atpredetermined intervals to elevate and depress the gripper members. Tothis end, as shown more particularly in Fig. 2,'-the rail is providedwith diagonal slots 17 Oand 172 engaged by threaded fastenings 174,which are mounted in brackets 175 connected to the upper side of one ofthe guides 114. The rail is moved longitudinally to elevate it throughthe members 174 and diagonal slots 170 and 172 by an arm 176 engagingat'its lower end between blocks 178 secured to. the rail. Thearm ispivoted at 180 on a stud projecting from one of the side frames 182. Thearm is provided with acam roll 184 intermediate its ends which contactswith the periphery of a cam 186 mounted on the shaft 130. The engagementbetween the cam roll and periphery of the cam is maintained by a spring190. During the longitudinal and elevating movement of the rail, themembers 174 act merely as guides and the side rail and cooperating partsare supported by rolls 192 journalled upon the guides'114 and engagingwith inclined faces 194 formed on the under side of the rail. With thisconstruction, lon itudinal movement of the side rail at pre e-.

termined intervals elevates the latter, and through the arm 166 impartsa corresponding elevation to the suction grippers 100, bringing thegrippers into the position shown more particularly in Fig. 4.

It will be evident that irrespective of the length of the sheets inprocess of delivery to the press mechanism, the position of the forwardedge of the bank will be determined by the members 152. Means areprovided for varying the position of the assembly for engaging an'dbuckling the rear portion of the sheet in accordance with variations inthe length and width of the sheet being operated J upon. To this endeach of the heads 56 supporting the gripper and hold-down assembly "1Sslidably mounted on cross shafts 200- and 202, .as shown moreparticularly in F1gs.- 3 and 5. The heads are retained in ad usted.

position by clamping screws 204, and 206 mounted in the heads andengaging the shaft. It will be evident that by loosening the clampscrews the heads, each carrying the gripper.

and hold-down assembly, may be adjusted transversely of the mechanism tovary the engagement of the members in accordance with the width. of thesheet. The longitudinal position of the two assemblies with respect tothe forward edge of the-bank may be varied in the following manner. Theshaft 202 is provided at .opposite ends with teeth 207 which mesh withrack teeth 208 formed in the upper portion of the side rails 116, as

' indicated more particularly in Figs. 3 and 5. This shaft is alsojournalled at opposite ends tion of the rearsuction grippers, the

in slide bearings 210, each of which is provided with an under guide 212engaging with the bottom portion of the side rail 116. The

slide bearings 210, in addition; form bearings for the opposite ends ofthe transverse shafts 200 and 202. With this construction, uponloosening the clamp screws 206, the shaft 202 may be rotated by a handwheel 214 to traverse the shafts and assemblies carried thereby towardor from the forward gripper assembly. Upon completion of the adjustment,

the assembly is held rigidly in the desired position by -tightening theclamp screws. The forward gripper mechanism may be adjusted tocompensate-for variations in the width of the sheet by loosening theclamp screw 216 and adjusting the arms 154 and gripper assembly carriedthereby'transverseand intermediate its ends is provided withsupportingbrackets 222 connected, thereto for transverse adjus ment. Each of thesebrackets 222 is provi ed with a hub portion jdfirnalled on the shaft130, and provides a bearing for a spiral gear 224 mounted on a stubshaft 226. Each of these stub shafts is connected through the universaljoint 64 with the telescoping drive shaft. The spiral gear 224 mesheswith a similar drive gear 228 connected to the transverse shaft andoperatedf thereby. With this construction the telescoping shafts andconnected'parts are operated in timed relation with the remainder of themechanism.

i The vacuum is applied to and released from the front and back suctiongrippers, and a pressure current applied to and cut off from the blowernozzles automatically through the mechanism shown more particularly inFig. 8. This mechanism comprises a valve-casing 230 supported from thetransverse shaft 220 through a bracket 232 shown termediate the brackets222." Sliding within the valve casing are a series of valves 234, 236and 238which control respectively the o. erasuction grippers and theblower nozzles. The position of these sliding valves is automaticallydetermined by cams 240, 242 and 244 mounted on the shaft 130. Each valveis provided with a roll 246 in the lower end which is maintained incontact. with the periphery of the respective cam by a spring 248interposed between the upper end of the valve and ont - front suctiongrippers.

,is mounted on the end of sup lengthwise of the feed through municationbetween the common supply and vacuum pipes 258 and 260 connecting withthe rear suction grippers. The passage 252 I and the valve 236 aflordcommunication between the common supply and the flexible connections 150communicating with the The valve 238 is provided with a passage 264which affords communication between 'a source of pressure 266 and pipes268 connected with the blower nozzles 93. With this "construction itwill be evident that the application and release of the vacuum andpressure may be properly coordinated in the separation and delivery ofthe individual sheets to the mechanism of the ress. P The individualsheets after engagement and advance by the suction gripper mechanism areengaged by positioning mechanism which insures the location of the frontedge of the sheets in a predetermined position for engagement with thegrippers mounted on the cylinder of the press. To this end, as 1nd1-cated more particularly in Figs. 1 and 4, a positioning guide 270extends transversely above the rotating cylinder of the press and ortingbars 272 which project from heads 2 4 which are supported upon a crossshaft 276. The cooperating positioning members, indicated at 278 and279, engage and grip the front corners of the'sheet and advance thefront edge of the sheet into contact with the positioning bar 270. Eachset of positioning grippers is mounted on a slide 280 and isreciprocated an oscillatory arm 282 connected with the slide through alink 284. The arm is mounted on a cross shaft 286 supported in thebrackets 287 and is operated by mechanism to be presently described, toadvance and retract the posltioning grippers at predetermined intervals.The grippers are opened and closed during retraction through engagementof the upper gripper 278 with a stationary roll 288, .the

upper gripper being provided with a projecting arm 290 which rides overthe roll on forward movement of the grippers. This mechanism is onlybriefly described as specifically it forms no part of the presentinvention.

In the event that no sheet is presented to the positioning guide by thesheet separating or positioning mechanism, the operation of the press isstopped, permitting the difficulty to be remedied. In addition, if thesheet is improperly presented to the cylinder of the press or isimproperly engaged by the grippers upon the cylinder in such a mannerthat it does not hug the cylinder closely, the operation of the press isautomatically stopped.

mechanism is indicated more parand 4 and is intended to operate upon themain drive of the press which may consist of an electric motor, theoperation of which is governed by a circuit controlling switch of, anyconventional type. This circuit controlling switch (not shown) or anycontrolled through an actuating rod 291, as shown in Fig. 1, connectedat its upper end to a bell crank lever 292 pivoted upon a bracket 294bolted to the side of the bed 20. The bell crank lever 292 is connectedto the stop mechanism through a link 296 loosely engaged at its oppositeend with the forked end of an oscillatory arm 298. Connection betweenthe arm and link is provided through a projection 300 formed on the armwhich engages in a notch 302 formed in the lower endof a shoe 304mounted on the link. In the normal operation of the press the arm 298remains stationary, but in the event that no sheet is fed to thecylinder or that the sheet is buckled This stop ticularly in Figs. 1

or wrinkled, stop mechanism is set inmotion to cause operation of thearm at a predetermined point in the cycle of operations of the press todisconnect the main drive. The operation of this stop mechanism is inpart controlled by a depending finger 306 which is loosely pivoted at308 adjacent the guide 270. This finger is provided with a transverseprojection 310 which in the position shown in Fig. 4 engages behind athreaded collar 312 mounted on a rod 314. The rod 314 at its forward endis received loosely within a supporting head and at its rear end isconnected with an arm 316 mounted on the shaft 286. The arm 316 isconnected with a second arm 318 which tends to operate the arm 316 atpredetermined intervals' The arm 318 is connected through a link 320with one arm 322 of a hell crank lever having a second arm 324, all asshown in Fig. 4, the bell crank lever oscillating about a shaft 326. Thebell crank lever is provided at the outer end of the arm 324 with a camroll 328 which engages with the periphery of a cam 330 mounted on theshaft 332. The roll tends to maintain engagement with the cam through aspring 334 connecting the arm 324 with a portion of a bracket 336. Itwill be evident from this construction that the cam 330 constantlyrotates during the operation of the press and tends to impart areciprocating motion to the rod 314 and the interconnected parts. In theevent that a sheet is engaged by the positioning grippers and advancedinto engagement with the uide 27 0, the projecting portion 310 of theger is depressed below the collar 312, permitting the recipro catingmovement to take place. When no sheet is presented, however, theprojecting portion 310 of the finger remains in engagement with thecollar and revents movement of the rod and attached 00 an Thisengageother desired form of drive may be ment of the finger and thecollar occurs when the roll 328 is opposite the depressed portion of thecam, and normally tends to fol ow the cam through the action of thespring 334. Connected with the arm 318 is an operating link 340 which atits lower end engages with the tail of a pawl 342 pivoted at 344'on anoscillatory arm 346. The nose 348 of the pawl engages in a notch 350formed in the hub 352 of the arm 298. The arm 346 carrying the pawl 342is connected with a second arm 354, the two arms forming a bell crankmounted on the shaft 326. These arms are oscillated at predeterminedintervals about the shaft 326 bya constantly rotating cam 356 engaged bya cam roll 358 mounted on the arm 354 and held in engagement with thecam by a spring 360 when the pawl 342 is engaged in the notch 350. Theoscillatory movement of the arm 346 carrying the pawl together with theconnected members imparts a like movement to the arm 298 through the hub352. In the normal operation of the machine, however, the engagement ofthe sheet with the'finger releases the rod 314,

permitting a withdrawal of the rod and depression of the arm 318 with aconsequent movement of the link 340 to disengage the nose 348 of thepawl from the notch 350. When this occurs the oscillatory movement ofthe arm 346 carrying the pawl fails to impart any movement to the hub352 and the arm 298 connected therewith. On the other hand, when nosheet is presented, the rod 314 is held against withdrawal, the rod 340is not depressed, and the pawl 342'remains in engagement with the notchthrough the provision of the weight 362 causing the arm 298 to beoscillated upon oscillatory movement of the arm 346 by the cam 356, thisoscillatory movement being communicated to the main drive through theactuating rod 296 previously described. Both cams 330 and 356 aremounted on the shaft 332 supported on the side of'the press and operatedfrom the cylinder shaft 364 through intermeshing spur gears 366 and 368.It will be'evident from an inspection of Fig. 4 that the movements ofthe arm 298 to throw olf the drive limited by the engagement of a. lug370 formed on the arm with'the oppositely dis-' posed legs 372 and 374of a stationary .bracket 380 secured to the shaft 326. The actuat-.

ing link 340 passes-loosely through the tail of the pawl 342 at itslower end, and is provided with a collar 281 threaded thereon en gagingwith the top portion of the pawl to remove it from operative positionduring the norinal operation of the machine. The return of the pawlintoengagement with the notch 350 is accomplished by the weight 362.-

' sirableto stop the machine. For this .pose one or more elongatedfeeler mem ers In the event that the sheet is improperly clamped uponthe cylinder, it is likewise desheet during the delivery of the sheet bynectedto a rocker arm 388 which in turn is connected to the shaft 384.This actuating rod at its lower end is connected with a rocker arm 390provided with a cam face 392 which rides under a sleeve 394 mounted uponthe link 320. The movementof the cam projection 392 beneath the sleeve394 prevents downward movement of'the link 320 together with itsconnected parts, and causes thepawl 342 to remain in engagement withthenotch 350 and oscillate the throw-off arm 298 upon oscillation of thearm carrying the pawl. It will be evident that in each case the machineis stopped at a predetermined point'in the cycle of operations and in apredetermined point in the movement 7 of the positioning grippers. newsheet and the starting of the press.- Furthermore, it will be evidentthat the mechanism for automatically stopping the opera- Thisfacilitates the insertion of'a as p ' tion of the press maybeconveniently attached to existing forms of'apparatus, the operat- I ingmechanism being supported from the side of the press and the feelermechanism being supported in the usual structure at the topof the press.The stop mechanism functions to stop the machine upon failure vof thepulloif guides either to present a sheet to the positioning'mechanism orin the event that a sheet is positioned improperly or not in front edgere 'ster with the positioning mecha-- the invention may be embodied inother types of feeding mechanism.

Whatis claimed is: v

1. A sheet feeding machine comprising a feed table, means for deliveringa continuous bank of feathered sheets over the table, means forelevatinor buckling the rear portion of the top s eet, suction carrier mechanismengaging with the front portion of the thus separated sheet andadvancing, the sheet to delivery position, and means. for supplying asupporting film of air beneath the separated suction carrier mechanism.

2. A sheet feedingmachine cd nprising a feed table, means for delivering'21, bank of the sheets to the table, suction separator devices engagingand elevating the rear portion of the top sheet to initiate theseparation of the sheet from the bank, suction carrier mechanismengaging with the front portion of the thus separated sheet andadvancing the sheet into delivery position, and means for interposing asupporting film of air beneath the top sheet during its advance by thecarrier mechanism.

3. A sheet feeding machine comprising a feed table, means for deliveringa bank of sheets to the table, suction separator devices engaging and,elevating the rear portion of the top sheet to initiate the separationof the sheet from the bank, suction carrier mecha nism engaging with thefront portion of the thus separated sheet and advancing the sheet intodelivery position, means for rendering the suction separatorsinoperative during the advance of the sheet, and means for maintaining asupporting film of air beneath the sheet during its advance by thecarrier mecha nism.

4. A sheet feeding machine comprising a feed table, means for deliveringa pile of sheets to the table, means for engaging and holding down therear corner of the upper sheetat inner and outer separated points,'asuction device for engaging and buckling the rear corner of the uppersheet, means for removing the outer hold-down from operative positionduring the buckling of the corner and for thereafter returning theholddown to engagethe pile beneath.

5. A sheet feeding machine comprising a feed table, means for deliveringa continuous bank of feathered sheets to the table, devices for engagingand buckling a corner of the top sheet, means for holding down the sheetat opposite sides of the point of engagement, constructed and arrangedto initially release that portion of the sheet outside of the de vicesand permit buckling while maintaining the inner portion of the sheet inengagement with the bank.

6. A sheet feeding machine comprising a feed table, means for deliveringa continuous bank of feathered sheets to the table, means for pressingthe top sheet against the pile,

means for engaging and buckling the rear out-' er corners of the topsheet, means for releasing a portion of the sheet to permit buckling,carrier mechanism for engaging the front portion of the sheet andadvancing the sheet bodily into delivery position, and means forcompletely releasing the rear portion of the sheet after its engagementby the carrier mechanism.

7. A sheet feeding machine comprising a supporting table for acontinilous bank of feathered sheets, means for engaging the rearcorners of the top sheet at inner and outer separated points to holddown the sheet,

means for engaging and buckling the rear corners of the top sheet, meansfor releasing the hold-downs at the outer points to permit buckling, andsuction devices engaging with the front portion of the top sheet andadvancing the sheet into delivery position.

8. A sheet feeding machine comprising a feed table supporting a pile ofsheets, heads slidable transversely of the pile of sheets, suctionbuckling and hold-down devices carriedby each head, mechanism mounted onthe head for operating the devices, and a device mounted on each headfor interposing a supporting film of air beneath the top heet elevatedby the buckling devices.

9. A sheet feeding machine comprising a feed table, means for deliveringa continuous bank of sheets to the table, suction carriers engaging thefront portion of the top sheet at opposite corners, slides supportingthe carriers, means for reciprocating the slides in unisonlongitudinally of the table to advance the sheet engaged by thecarriers, means for applying and releasing suction to and from thecarriers, and means for elevating the carriers at the completion oftheadvancing movement to permit return of the carriers to initialposition without interference with the sheet.

10. A sheet feeding machine comprising a feed table, a carriage slidablelongitudinally I suction carriers for engagement'with the top sheet ofthe bank at opposite sides, slides supporting the carriers, means forreciprocating the slides longitudinally of the table, means forsupporting the carrier for vertical movement with relation to theslides, and means for automatically elevating the carriers at thecompletion of the advancing movement of the slides.

12. A sheet feeding machine comprising a table for supporting a pile ofsheets, suction carriers for engaging the top sheet 'of the pile,toothed slides supporting the carriers, a pinion for reciprocating eachslide, a common actuating mechanism for operating the pinions in unison,a cam, and connections be-' tween the cam and carriers for elevating thecarriers with relation to the slides on com-- use ' vancing movement ofthe slide to elevate the carrier With relation thereto.

14. A paper-feeding machine comprising a feed table, means fordelivering a continuous bank of sheets to the feed table, a positioningguide, gripper members positioned in advanceof the guide to receive thesheet, suction carrier designed to engage the front portion of the topsheet and elevate it bodily from the bank means for advancing thecarriers through a relatively short space sulficient to cause engagementof the front edge by the grippers, and means for supporting the sheet onan air film during its advance by the carriers.

15. A sheet feeding machine comprising a table for supporting a pile ofsheets, means for vibrating the rear portion of the top sheet, means forengaging andholding the vibrating portion of the sheet in an elevatedposition separated from the pile therebeneath, hold-downs arrangedoutside of the sheet engaging means to engage the bank after thevibrating portion of the sheet is elevated, and means for thereafteradvancing the sheet into delivery position.

16. A sheet feeding machine comprising a table for supporting a pile ofsheets, means for vibrating the rear portion of the top sheet, means forengaging and holding the vibrating portion of the sheet in an elevatedposition separated from the pile therebeneath, hold-downs arrangedoutside of the sheet engaging means to engagethe bank after thevibrating .ortion of the sheet is elevated, means for t ereafteradvancing the sheet into delivery position, and means for releasing therear portion of the sheet after engagement by the delivery means.

17. A sheet feeding machine comprising a feed table, means fordelivering a continuous bank of sheets over the table, means forseparating the leading sheet from the bank, and

hold-down devices operating to first release the leading sheet andthereafter engage the bank therebeneath during the operation of theseparator means. 8

18. A sheet feeding machine comprising a feed table, means, fordelivering a continuous bank of sheets over the table, means forseparating the leading sheet from the bank,- inner and outer hold-downs,and means for first releasing the outer hold-down and thereafterreleasing the inner hold-down and applying the outer hold-down.

19. A sheet feeding machine comprising a feed table, means fordelivering a continuous bank of sheets over the table, means forseparating the leadin sheet from the bank, inner and outerholdowns,means for intermitvaries.

FRANK L. CROSS. HENNING HALLSTREAM.

